Boron-based multiple-resonance (MR) emitters exhibit the advantages of narrowband emission, high absolute photoluminescence quantum yield, thermally activated delayed fluorescence (TADF), and sufficient stability during the operation of organic light-emitting diodes (OLEDs). Thus, such MR emitters have been widely applied as blue emitters in triplet-triplet-annihilation-driven fluorescent devices used in smartphones and televisions. Moreover, they hold great promise as TADF or terminal emitters in TADF-assisted fluorescence or phosphor-sensitised fluorescent OLEDs. Herein we comprehensively review organoboron-based MR emitters based on their synthetic strategies, clarify structure-photophysical property correlations, and provide design guidelines and future development prospects.

Organoboron-based multiple-resonance emitters: synthesis, structure-property correlations, and prospects.

Designing multi-resonance (MR) emitters that can simultaneously achieve narrowband emission and suppressed intermolecular interactions is challenging for realizing high color purity and stable blue organic light-emitting diodes (OLEDs). Herein, a sterically shielded yet extremely rigid emitter based on a triptycene-fused B,N core (Tp-DABNA) is proposed to address the issue. Tp-DABNA exhibits intense deep blue emissions with a narrow full width at half maximum (FWHM) and a high horizontal transition dipole ratio, superior to the well-known bulky emitter, t-DABNA. The rigid MR skeleton of Tp-DABNA suppresses structural relaxation in the excited state, with reduced contributions from the medium- and high-frequency vibrational modes to spectral broadening. The hyperfluorescence (HF) film composed of a sensitizer and Tp-DABNA shows reduced Dexter energy transfer compared to those of t-DABNA and DABNA-1. Notably, deep blue TADF-OLEDs with the Tp-DABNA emitter display higher external quantum efficiencies (EQEmax = 24.8%) and narrower FWHMs (< 26 nm) than t-DABNA-based OLEDs (EQEmax = 19.8%). The HF-OLEDs based on the Tp-DABNA emitter further demonstrate improved performance with an EQEmax of 28.7% and mitigated efficiency roll-offs.

Triptycene-Fused Sterically Shielded Multi-Resonance TADF Emitter Enables High-Efficiency Deep Blue OLEDs with Reduced Dexter Energy Transfer.

Highly efficient and stable blue organic light-emitting diodes (OLEDs), although required for display and lighting applications, remain rare. Here we report a molecular perdeuteration strategy to stabilize blue thermally activated delayed fluorescence (TADF) emitters. Perdeuterated sky-blue TADF emitters exhibit higher efficiencies and doubled device lifetime in OLEDs compared with protonated emitters, owing to suppressed high-energy vibrations. Perdeuteration also leads to blue-shifted and narrowed spectra in the solid state, which in turn improves the Förster energy transfer to the deep-blue final emitter in TADF-sensitized fluorescent OLEDs. These devices exhibit a maximum external quantum efficiency of 33.1% and a lifetime to reach 80% of the initial luminance of 1,365 h with a Commission Internationale de l’Eclairage y coordinate of 0.20 at a luminance of 1,000 cd m−2, even outperforming blue phosphorescent OLEDs. Our perdeuteration strategy improves the device performance of blue OLEDs, paving the way for their broader applications in displays and lightings. Molecular perdeuteration of thermally activated delayed fluorescence emitters improves the performance of blue organic light-emitting diodes, enabling a peak external quantum efficiency of 33.1% and a device lifetime to reach 80% of initial luminance of over 1,300 h.

Enhancing the efficiency and stability of blue thermally activated delayed fluorescence emitters by perdeuteration

Abstract The 3 rd -Gen OLED materials employing thermally-activated delayed fluorescence (TADF) combine advantages of first two for high-efficiency and low-cost devices. Though urgently needed, blue TADF emitters have not met stability requirement for applications. It is essential to elucidate the degradation mechanism and identify the tailored descriptor for material stability and device lifetime. Here, via in-material chemistry, we demonstrate chemical degradation of TADF materials involves critical role of bond cleavage at triplet state rather than singlet, and disclose the difference between bond dissociation energy of fragile bonds and first triplet state energy (BDE- E T1 ) is linearly correlated with logarithm of reported device lifetime for various blue TADF emitters. This significant quantitative correlation strongly reveals the degradation mechanism of TADF materials have general characteristic in essence and BDE- E T1 could be the shared “longevity gene”. Our findings provide a critical molecular descriptor for high-throughput-virtual-screening and rational design to unlock the full potential of TADF materials and devices. 

/pdf/longevity-gene-responsible-for-robust-blue-organic-materials-jla6gxk6.pdf

Longevity gene responsible for robust blue organic materials employing thermally activated delayed fluorescence

Multiple resonance (MR) compounds have garnered substantial attention for their prospective utility in wide color gamut displays. Nevertheless, developing red MR emitters with both high efficiency and saturated emission color remains demanding. We herein introduce a comprehensive strategy for spectral tuning in the red region by simultaneously regulating the π-conjugation and electron-donating strengths of a double boron-embedded MR skeleton while preserving narrowband characteristics. The proof-of-concept materials manifested emissions from orange-red to deep red, with bandwidths below 0.12 eV. The pure-red device based on CzIDBNO displayed superior color purity with CIE coordinates of (0.701, 0.298), approaching the Broadcast Television 2020 standard. In concert with high photoluminescence quantum yield and strong horizontal dipole orientation, CzIDBNO also achieved a maximum external quantum efficiency of 32.5% and a current efficiency of 20.2 cd A-1, outstripping prior reported organic light-emitting diodes (OLEDs) with CIEx exceeding 0.68. These findings offer a roadmap for designing high-performance emitters with exceptional color purity for future OLED material research advancements. 

Precise modulation of multiple resonance emitters toward efficient electroluminescence with pure-red gamut for high-definition displays

Phosphorescent and thermally activated delayed fluorescence (TADF) blue organic light-emitting diodes (OLEDs) have been developed to overcome the low efficiency of fluorescent OLEDs. However, device instability, originating from triplet excitons and polarons, limits blue OLED applications. Here, we develop a phosphor-sensitized TADF emission system with TADF emitters to achieve high efficiency and long operational lifetime. Peripheral carbazole moieties are introduced in conventional multi-resonance–type emitters containing one boron atom. The triplet exciton density of the TADF emitter is reduced by facilitating reverse intersystem crossing, and the Förster resonant energy transfer rate from phosphor sensitizer is enhanced by high absorption coefficient of the emitters. The emitter exhibited an operational lifetime of 72.9 hours with Commission Internationale de L’Eclairage chromaticity coordinate y = 0.165, which was 6.6 times longer than those of devices using conventional TADF emitters.

https://www.science.org/doi/pdf/10.1126/sciadv.abq1641?download=true

Highly efficient and stable deep-blue organic light-emitting diode using phosphor-sensitized thermally activated delayed fluorescence

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Mieun Jun

Author Tools

Chat about Author

Papers

Highly efficient and stable deep-blue organic light-emitting diode using phosphor-sensitized thermally activated delayed fluorescence